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 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */

package java.awt.datatransfer;

import java.io.*;


/**
 * A <code>Transferable</code> which implements the capability required
 * to transfer a <code>String</code>.
 *
 * This <code>Transferable</code> properly supports
 * <code>DataFlavor.stringFlavor</code>
 * and all equivalent flavors. Support for
 * <code>DataFlavor.plainTextFlavor</code>
 * and all equivalent flavors is <b>deprecated</b>. No other
 * <code>DataFlavor</code>s are supported.
 *
 * @see java.awt.datatransfer.DataFlavor#stringFlavor
 * @see java.awt.datatransfer.DataFlavor#plainTextFlavor
 */
public class StringSelection implements Transferable, ClipboardOwner {

  private static final int STRING = 0;
  private static final int PLAIN_TEXT = 1;

  private static final DataFlavor[] flavors = {
      DataFlavor.stringFlavor,
      DataFlavor.plainTextFlavor // deprecated
  };

  private String data;

  /**
   * Creates a <code>Transferable</code> capable of transferring
   * the specified <code>String</code>.
   */
  public StringSelection(String data) {
    this.data = data;
  }

  /**
   * Returns an array of flavors in which this <code>Transferable</code>
   * can provide the data. <code>DataFlavor.stringFlavor</code>
   * is properly supported.
   * Support for <code>DataFlavor.plainTextFlavor</code> is
   * <b>deprecated</b>.
   *
   * @return an array of length two, whose elements are <code>DataFlavor. stringFlavor</code> and
   * <code>DataFlavor.plainTextFlavor</code>
   */
  public DataFlavor[] getTransferDataFlavors() {
    // returning flavors itself would allow client code to modify
    // our internal behavior
    return (DataFlavor[]) flavors.clone();
  }

  /**
   * Returns whether the requested flavor is supported by this
   * <code>Transferable</code>.
   *
   * @param flavor the requested flavor for the data
   * @return true if <code>flavor</code> is equal to <code>DataFlavor.stringFlavor</code> or
   * <code>DataFlavor.plainTextFlavor</code>; false if <code>flavor</code> is not one of the above
   * flavors
   * @throws NullPointerException if flavor is <code>null</code>
   */
  public boolean isDataFlavorSupported(DataFlavor flavor) {
    // JCK Test StringSelection0003: if 'flavor' is null, throw NPE
    for (int i = 0; i < flavors.length; i++) {
      if (flavor.equals(flavors[i])) {
        return true;
      }
    }
    return false;
  }

  /**
   * Returns the <code>Transferable</code>'s data in the requested
   * <code>DataFlavor</code> if possible. If the desired flavor is
   * <code>DataFlavor.stringFlavor</code>, or an equivalent flavor,
   * the <code>String</code> representing the selection is
   * returned. If the desired flavor is
   * <code>DataFlavor.plainTextFlavor</code>,
   * or an equivalent flavor, a <code>Reader</code> is returned.
   * <b>Note:</b> The behavior of this method for
   * <code>DataFlavor.plainTextFlavor</code>
   * and equivalent <code>DataFlavor</code>s is inconsistent with the
   * definition of <code>DataFlavor.plainTextFlavor</code>.
   *
   * @param flavor the requested flavor for the data
   * @return the data in the requested flavor, as outlined above
   * @throws UnsupportedFlavorException if the requested data flavor is not equivalent to either
   * <code>DataFlavor.stringFlavor</code> or <code>DataFlavor.plainTextFlavor</code>
   * @throws IOException if an IOException occurs while retrieving the data. By default,
   * StringSelection never throws this exception, but a subclass may.
   * @throws NullPointerException if flavor is <code>null</code>
   * @see java.io.Reader
   */
  public Object getTransferData(DataFlavor flavor)
      throws UnsupportedFlavorException, IOException {
    // JCK Test StringSelection0007: if 'flavor' is null, throw NPE
    if (flavor.equals(flavors[STRING])) {
      return (Object) data;
    } else if (flavor.equals(flavors[PLAIN_TEXT])) {
      return new StringReader(data == null ? "" : data);
    } else {
      throw new UnsupportedFlavorException(flavor);
    }
  }

  public void lostOwnership(Clipboard clipboard, Transferable contents) {
  }
}
